کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
924004 921174 2013 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Developmental dissociation of visual dorsal stream parvo and magnocellular representations and the functional impact of negative retinotopic BOLD responses
موضوعات مرتبط
علوم زیستی و بیوفناوری علم عصب شناسی علوم اعصاب شناختی
پیش نمایش صفحه اول مقاله
Developmental dissociation of visual dorsal stream parvo and magnocellular representations and the functional impact of negative retinotopic BOLD responses
چکیده انگلیسی


• Neurodevelopmental functional dissociations between parvo/magnocellular pathways.
• Specific dorsal stream based impairment in regions V3A and V6.
• Damage of low and high level motion representations with parvocellular sparing.
• Contralateral spread of negative BOLD relates to loss of magnocellular performance.

Localized neurodevelopmental defects provide an opportunity to study structure–function correlations in the human nervous system. This unique multimodal case report of epileptogenic dysplasia in the visual cortex allowed exploring visual function across distinct pathways in retinotopic regions and the dorsal stream, in relation to fMRI retinotopic mapping and spike triggered BOLD responses.Pre-surgical EEG/video monitoring, MRI/DTI, EEG/fMRI, PET and SPECT were performed to characterize structure/function correlations in this patient with a very early lesion onset. In addition, we included psychophysical methods (assessing parvo/konio and magnocellular pathways) and retinotopic mapping.We could identify dorsal stream impairment (with extended contrast sensitivity deficits within the input magno system contrasting with more confined parvocellular deficits) with disrupted active visual field input representations in regions neighboring the lesion. Simultaneous EEG/fMRI identified perilesional and retinotopic bilaterally symmetric BOLD deactivation triggered by interictal spikes, which matched the contralateral spread of magnocellular dysfunction revealed in the psychophysical tests. Topographic changes in retinotopic organization further suggested long term functional effects of abnormal electrical discharges during brain development.We conclude that fMRI based visual field cortical mapping shows evidence for retinotopic dissociation between magno and parvocellular function well beyond striate cortex, identifiable in high level dorsal visual representations around visual area V3A which is consistent with the effects of epileptic spike triggered negative BOLD.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Brain and Cognition - Volume 83, Issue 1, October 2013, Pages 72–79
نویسندگان
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